The present invention relates to an insufflator for introducing limited quantities of carbon dioxide into the human body for operational purposes, particularly laparoscopy, comprising two pressure reducers followed by a gas flow monitoring device through which the carbon dioxide is directed to the body from the gas supply. For a gentle enlargement of body cavities, particularly in laparoscopy, but also in the hysteroscopy, it is usual to insufflate carbon dioxide into the human body, under a pressure which is adapted to the given conditions. In laparoscopy, a Verres needle is connected to the insufflator by means of a flexible tubing and, in the hysteroscopy, a hysteroscope is connected.
In a known insufflator of the mentioned kind, the gas flow monitoring device comprises a vertically extending glass tube which is mounted outside the insufflator and accommodates a floating ball which is vertically movable under the action of the gas stream. The device is used, in connection with a pressure gage and a pressure reducer switchable automatically or manually, for checking the carbon dioxide quantity supplied by the insufflator. With a manual actuation of the pressure reducer, the admissible intraabdominal pressure may be substantially exceeded so that, upon a possible wrong actuation of such an insufflator, a pressure level may be adjusted which is dangerous to the life of the patient. For example, this may occur when the pressure reducer has been switched to hand operation and an attempt is made to determine the probable position of the Verres needle according to the indication of the pressure gage and the position of the floating ball. Evidently, and this is exactly the criterion of security, in case of an erroneous actuation, i.e., without having switched the pressure reducer to automatic operation, the patient is not sufficiently protected.